Biology 102

You observe a vesicle moving toward the plasma membrane from inside a cell. Once it reaches and fuses with the plasma membrane, you will most likely see an example of:

Extocytosis

The following figure illustrates a plasma membrane. Which substance in the figure is crossing the membrane using simple diffusion?

H2O

Three stages of aerobic respiration are:

glycolysis, the Krebs cycle, and oxidative phosphorylation

As a biological process, osmosis:

is a type of passive transport

This diagram depicts the Calvin cycle, which is a series of enzymatic reactions that manufactures sugars. How many times must this cycle "turn" to fix enough carbons to make one molecule of glucose?

6 times

Which type of molecule will diffuse through the plasma membrane most quickly?

A small nonpolar molecule like carbon dioxide

Which of the following would directly supply energy to an active carrier protein?

ATP

Which of the following statements comparing photosynthesis with cellular respiration is true?

Both photosynthesis and cellular respiration require electron transport chains.

Heat speeds up chemical reactions by:

Causing reactants to collide more often

Active transport requires:

Cellular energy, usually in the form of ATP

When ATP breaks apart into ADP and a free phosphate group, which of the following processes occurs?

Energy is released and can be used to power cellular activities

In the following flowchart summarizing membrane transport, both active and facilitated transports terminate at separate carrier proteins. Which statement explains why the lines do not converge at the same carrier protein?

Energy is required to drive an active transport carrier protein, whereas a facilitated carrier operates down the concentration gradient and requires no energy input.

All of the following elements can be found in the photosynthetic intermediary molecules that lead to the production of sugar; which element does NOT remain in the final product (glucose)?

Nitrogen

The following figure shows the movement of solutes across a plasma membrane in the direction indicated by the arrows. This movement across the membrane:

Occurs by facilitated diffusion.

What is the importance of photosynthesis to organisms other than plants?

Photosynthesis captures energy that other organisms access when they eat either plants or organisms that eat plants.

Animal cells are attached to neighboring cells by all of the following, EXCEPT:

Plasmodesmata

During photosynthesis, light energy is converted into chemical energy, which is a type of:

Potential energy

Most cell surface receptors of chemical messages are made of

Protein

Most enzymes are members of a special class of:

Proteins

The outcome of the Calvin cycle is the:

Synthesis of sugars like glucose, fructose, and sucrose

The second law of thermodynamics states that:

Systems tend to become more disorderly

It is reasonable to say that our brain is solar powered because:

The antenna complex in chloroplasts acts like a tiny solar panel, collecting sunlight to make the sugars we consume to run our brain.

All movement, including that of diffusing molecules, requires a small expenditure of energy; which of the following small sources of energy is most likely to make diffusion possible across the cell membrane from the cell exterior into the cell interior?

Thermal (kinetic) energy is present in the extracellular environment

In many organelles, groups of different enzymes are located on membranes in close proximity to each other. Why?

These enzymes are involved in the same metabolic pathway; keeping them closer together increases the pathway's efficiency

Which of the following statements best describes how extremes of pH often disrupt the function of enzymes?

They alter the structure of the enzyme's active site.

Viruses are generally not considered to be "alive" for all of the following reasons EXCEPT:

They are capable of evolving

This figure is a diagram of the inner mitochondrial membrane. How did the protons (H+ ions) in the diagram become concentrated on one side of the membrane?

They were pumped across the membrane by the electron transport chain.

The light-capturing pigments of photosynthesis like chlorophyll are contained in the membrane of a structure known as a(n):

Thylakoid

This illustration diagrams the action of an enzyme. Notice that the enzyme is more tightly wrapped around the substrate in step 2 than it is in step 1. Why?

When a substrate locks into an enzyme's active site, the enzyme changes shape to mold itself around the substrates.

Which statement best describes the equilibrium condition shown in the following illustration below?

a sample taken from anywhere in the container will have the same concentration of solute (kool-aid)...

The concentration of glucose inside a cell is higher than the concentration outside that cell, yet glucose continues to enter the cell. This is an example of:

active transport

The enzyme RUBISCO is important to the process of:

carbon fixation

During the process of photosynthesis, plants capture the kinetic energy of moving photons and transform it into potential energy in the form of:

chemical (carbon) bonds

Glycolysis occurs in a cell's:

cytosol

Hikers can detect a dead skunk along a trail long before they actually see it. What process allows the scent of the skunk to be so widely dispersed?

diffusion

The energy required for life processes must be extracted from an organism's:

environment

In the chemical reaction H20+CO2+ carbonic anhydrase ---> H+HCO3- + carbonic anhydrase, the carbonic anhydrase is a(n).

enzyme

Which of the following conditions destroys the three-dimensional structure of proteins?

major change in normal pH and/or temperature levels

Which of the following components contribute to the structure of the cytoskeleton of a cell?

microtubules and actin filaments

Which of the following is found in plants?

plasmodesmata

In the chemical reaction C6H12O6+602-----> 6CO2+6H2O, the 6 CO2 molecules are some of the:

products

In photosynthesis, the carbon used to make sugars is:

provided by carbon dioxide

After glycolysis, the 6-carbon glucose molecule has been split into 2 molecules of the 3-carbon compound ____ that will then move inside the mitochondrion for completion of aerobic respiration:

pyruvate

Multicellular organisms have various specialized cells because:

specialized cells ensure that processes necessary for life occur efficiently

Each time we take a breath, we are bringing in oxygen we need to stay alive. The ultimate source of the oxygen used by all aerobic organisms comes from a reaction that:

splits water

Photosynthetic organisms capture energy from sunlight and convert it into chemical binds by forming:

sugars

Most of the reactions that allow NADH to pick up electrons during AEROBIC RESPIRATION in a mitochondrion and carry them to the ETC take place during:

the Krebs cycle

Consider the change in the status of the polymers in the living cell and the dead cell, as shown in the illustration. Which of the following natural processes would best exemplify this change?

the decomposition of a fallen tree trunk on the forest floor

Enzymes can catalyze a chemical reaction only if:

they encounter a substrate that fits their active site

The photosynthetic reactions that are dependent on light occur in the:

thylakoid membrane